Process of extracting resin and turpentine.



- G. WALKER.

rnoczss 0P EXTRACTING RESIN AND TURPBNTINE.

APPLICATION FILED MAY 9, 190B.

, 922,369. Patented May 18, 1909.

uwmtoz w, wmswca WWW To all whom it may concern:

UNITED STATES PATENT *orr ron.

GEORGE WALKER, OF, NEW YORK, 'N. Yl, ASSIGNOR TO HOMER r. YARYAN, or ToLEDo, onio.

raocnss OF ex raacrme' RESIN AND TURPENTINE.

[not 922,369.

Specification of Letters Patent.

Patented May 18, 1909.

Application med May 9,1903. Serial No. 431,757I

Be it 'known that I, GEORGE citizen of the United States, residing at New York, in thecounty andState of New York, have invented certain new and useful/Improvements in Processes of Extracting Resin and Turpentine, whereof the following is a specification.

This lnvention relates to processes of extractingresin and turpentine; and comprises a method ofextractmg tur entine and resin from coniferous ,Woods in w rich such wood is first freed from turpentine, volatile terpenes, etc., by distillation under conditions. injurious neither to the turpentine nor the resin and is subsequently extracted With a volatile solvent body to obtain a pure. resin; all as more fully hereinafter set forth and as claimed.

In the prior art, coniferous wood has been directly extracted-with various solvents, hydrocarbons being generally employed, toobtain rosin and turpentine at one o eratiori. The extract obtained contains boti bodies, together with the solvent em loyed, and is distilled to remove, first the so vent and then the tur "cntine, the rosin being left behind in the stil as a residue. This method however sufiers rrom a number of disadvantages and d wood constituents or products other than turpentine, while the rosin generally suffers in clearness, color and quality by the repeat ed distillations necessar to free it'of the solvent employed and-otturpentine, a high tern er'aturebeing usually employed in such fdisti lations. Rosin does not well withstand long continuance of high temperatures.

I s. I Since even volatile commercial hydrocarbons like gasole ne and naphtha, contain high-boiling impurlties such impurities tend to contaminate the turpentine.

In the present process I have devised a simple, cheap and ready method of preparing a pure rosin and tur entine of good commercial grades, this met 0d obviating the stated disadvantages and securing certain newv advantages. According to this, invention, I preliminarily treat the wood, which may be any of the coniferous woods, by a: distillation at comparatively low temperatures, that is,, temperatures at which neither the woody WALKER, a

fiber nor the resin will suffer pyrolytic decomposition or injurious changes and afford decomposition roducts to contaminate the distillation pro not. This distillation-gives me turpentinefileavin' the resin in the wood:

unchanged. .While t e distillation may be effected by sim le heating of the cornminuted WOO(l in thln ayers, or strata, since wood contains considerable water which in evaporating carries the turpentine with it, yet in practice it is better to use some form of,gaseous or vaporous carrier. Under the ordinary laws of evaporation, turpentine evaporates much more freely and at alower temperature into a gas mass carrying little of its' .own vapors than into a gas mass containing much of such vapors, so that it isdesirable to use'a considerable volumeof a gaseous: orvaporous carrier circulating past the Wood being distilled and absorbing and diluting the turpentine vapors as fast as formed. -Air I or neutral gases may be employed, the latter being better since an oxidizes turpentine and rosin, but steam is still better. I therefore preferably conduct the distillation bypassing I steam past or through the wood under treatment. The higher the temperature and 'pres-- sure of the steam the quicker the distillation may be effected, but steam under 10fl20 pounds pressure is perfectly suitable and is especially adapted to the present purposes.- while still lower pressures and the concomitant temperatures maybefeniployed. With steam of low temperature; whie the turpentine dist-ills over well, the grosinis not damaged. above thefl boiling point of tuilpentine, w ile the turpentine may be remove by the use of very little steam, yet the rosin'is apt terbeinjuriously affected'and to yield more or less rosin oil to contaminatethe turpentine."

The wood is preferably finely comminuted, in the form of sawdust or small chi s, such as, for example, those 'v'en by the sawmill hog. It may be distllled in thin Iayersor strata stationary or -moving, but when steam is employed, the use of such thin,

At temperatures approachin 'or layers or strata is not necessary and the com 1 minuted wood maybe in substantial masses of sawdust orfchi s and be contained in. any suitable vessel. g labor and expense,- this vesselis the same as referably however, to save that subsequently-employed for extraction.

Using steam, low pressure steam'is blown through or past the mass of wood-to and through a condenser of any ordinary type wherein it condenses together with the turp en-' tine vapors which it carries, the condensed water and turpentine being then gravitally se arated. The passage of steam and the dist' ation are discontinued when the condensate no longer separates substantial quantities of turpentine. The distilled wood, thus freed of turpentine andcontaining the residual rosin in a substantially unchanged state, is next extracted with a volatile solvent capable of dissolving rosin. 'While the'number of possible solvents which may be here employed is very large, almost any of the ordinary volatile solvents, that is, any of the ordinary, low-boiling, chemically neutral solvents, such as grain or wood alcohol, petroleum hydrocarbons, like gasolene, benzin or nalphtha, ether, methyl or ethyl acetate, benzo acetone, etc. being all more or less adapted for this purpose, I prefer to use a special distillate from hard wood tar as free from disadvantages for this purpose inherent in most of the other common solvents. Petroleum hydrocarbons, for instance, .while freely dissolving certain constituents of commercial rosin (from gum turpentine) do not dissolve other constituents so freely. Consequently in treating the wood with a limited quantity of gasolene, for instance, the solvent extracts more of certain resinous constituents of the wood-than of other constituents, and the resinous matter regained on evaporating the extract is not the same as rosinfrom gum tu entine.

n destructively distilling hard woods, the condensate contains many and difierent substances, the aqueous portion or pyroligneous acid containing besides acetic acid, acetone, methyl alcohol and water a considerable portion of oily bodies held in solution and suspension by the influence of the solvent bodies named while the non-aqueous portion, or tar, contains a still larger amount of these oily bodies. In urifying the pyroligneous acid these oily odies may be regained and the oily bodies may also be roduced by direct distillation of the tar. ertain fractions of the oily bodies from either source may be employed in the present invention. Using hard wood tar, ,the tar is distilled in a suitable'still till about half its weight passes over, the temperature of distillation being between 100 and 250 C. The first half of the distillate will consist of pyroligneous acid containing some wood spirit and of an oil li hter than water though containing some hig -boiling heavy oils codistilled therewith. The oil and acid are gravitally separated and the oil is next washed with water and with alkali to free it from acid and creosote and henolic bodies and render it neutral. It is t en redistilled in any suitable fractionating still to obtain the low boiling fractions, the fractions between C. and 100 being particularly suitable for the purifying pyrthe same as those obtained from wood-tar and may be treated in the same manner as above indicated for the distillate from tar.

After steani distilling Wood and before extracting with a solvent, the Wood is preferably dried by any suitable method to per mit good extraction since water-immiscible solvents do not Well, penetrate the dampfiber generally left by the treatment with low pressure steam while water-miscible solvents, such as alcohol, in taking up moisture lose much of their solvent power for rosin. Such drying is not absolutely necessary but it economizes in time and quantity of solvent employed. A convenient method is to follow the steam used in removing turpentine, etc., with a blast of air, sup lying some heat at the same time, either by eating the air or the wood.

In the accompanying illustration I have shown, more or less diagrammatically, certain types of apparatus of the many adapted for use in the described process. In this showing, the figure represents, part1 in cen-' tral vertical section and partly in e evation, a simple type of apparatus (chosen for illustration because of its simplicity) in which the preliminary distillation and the subsequent extraction are performed in the same vessel, but one such vessel being shown. In practice, however, a plurality of similar vessels will generally be employed; connected in well understood ways to permit a methodical use of the same portion of solvent on a plurality of portions of distilled wood in the same manner as in diffusion batteries, thereby obtaining concentrated solutions and economy in the use of solvent. In this figure, l'is the extraction and distillation vessel, provided with removable cover 2 secured by clamping means 3. At its base, the vessel is rovided with door 4. Internally the vesse is provided with steam heating means, shown as steam pipes 5 placed near the sides. At their base, they communicate with steam trap 6. Steam is furnished by steam main 7 from boiler 8. Another connection 9 from the steam main furnishes steam to a series of perforated steam pipes 10 or other suitable means for introducing live steam within the vessel. Pipe 11 connected to fan 12 allows the introduction of an air blast at the bottom of the vessel. Near the top of the vessel is pipe 13 allowing the introduction of rosin so vent from storage tank 1.4 while above it is vapor main 15 passing to condenser 16 of an of the ordinary ordinary type. At its base, this condenser is provided with a valved return pipe 17,- trapped at 18, to permit return of condenoutlet 24 for melted rosin: From the rosinv still leadsvapor pipe 25 to condenser 26 for the recovery of solvent. At its base, the condenser has'discharge pipe 27'leading to tank 28 from which ump 29 withdraws condensed'solvent an discharges it through piyie 30 to the storage tank for reuse. v

n the operation. of the a paratus shown and in performing the described'process, the

wood employed, w ich may be pine, light wood or any other orm of coniferous wood, in a commlnuted form, as sawdust, chi s, hogged wood, etc., is char ed into the 1s tillation and'extraction ve'sse and is subjected to a blast of steam from pipes 10. Heating may be assisted by steam/mcoils 5. The; steam, both that introduced and that formed from the moisture in the wood, passes outward through vapor main 15, carrying with it the 'volatilized turpentine. Water and turpentine are condensed in 16 and delivered through 19 into 20, 2O delivering the condensate to. any suitable containing vessels (not shown). When no more substantial amount of turpentine is found in the condensate, the direct steam is turneil ofi, the cover of the vessel removed and air blown through the wood to dry it and remove the steam and moisture. Drying may be hastened and fa cilitated by continuing the heating by steam coils"5 during the passage of the air. Ilot air may beemployed, but is hardly necessary since ,the coils furnish heat more conveniently. The first portions of air going through which will generally carry some steam and turpentine, may be sent to the condenser, but this is usually hardly worth while. I

When the wood is sufficiently dry and free of steam, the introduction of air isdiscontinned and sufficient solvent to cover the wood is introduced through pipe 13 from storage tank 14. This solvent is preferably the neutral volatile hardwood tar distillate described, but it may be another neutral volatile solvent. In'contact with the hot wood, the solvent is raised to the boiling. temperature and it is preferably maintainedat this temperature by the steam coils 5, extraction being better at high temperatures. Suchsolvent as volatilizes passes out through vapor main 15, is condensed in 16 and returns to the extractor through 17, the valve of pipe 19 being closed After contact with the wood the first portions of rosin solution.

for a sufficient time, the charged solvent or rosin solution may be drawn oil through 21 and sent to rosin still 22. Any rosin which, in the case of" such resinous materials as light wood, may have trickled down to the floor of the vessel during the steam distillation is dissolved by the solvent during the extraction and passes outward through 21 with After withdfawal of the first portion of solvent, another portion of fresh solvent, or solvent which has been previously used elsewhere, may be introduced if desired.

When the extraction is completed, as many portions of solvent having been used as may desired (and the ortions may be. used inethodically' in a p urality of vessels as stated, if ,so desired), the solvent remaining adherin to the wood is removed by passing in a litt e steam Which volatilizes it, the vae pors being allowed to ass through 15 into 16 and removed as liquii at 18, or-following the liquidextract, to pass throngh'21 into .22, thence-through 25, 26 and 27 into 28-. Having removed the solvent, the lower door of the extraction vessel is o ened and the exhausted wood dumped, 'eaving thevessel "ready for'another operation. The exhausted By separately extracting the turpentine and resin in the manner described, the quality of each is improved. In extracting them. together from the wood by solvents, as in the prior art, a mixture of solvent, turpentine and the resin, such as rosin,-is obtained from which solvent and turpentine must be fractionated, As turpentine boils at a comparatively high temperature, in removin the last fractions of the tur entine from $1151 a mixture there is apt to e some decomposition of the rosin, forming rosin oils which mix with the turpentine, injuring the quality of the rosin. And, in'using the petroleum oils as solvents, the turpentine is apt to be contaminated with. high-boiling impurities therefrom. Therosin itself is a t to be injured by the prolonged heatin at igh temperatures in removing the so vent a and turpentine, darkening in color. And, as stated, when removed from the wood by hydrocarbons, it is apt to be different in com osition from ordinary rosin. The describe neutral' tar distillate on the other hand gives a good quality of rosm.

While when employing the described lowboil'ing hardwood tar distillate as a solvent,

both turpentine and resin can be "simultaneously extracted,'yet I regard it as preferable to extract them successively in the manner described, first distilling off the turpen- -ward acid and alkali.

.tine and then" using the solvent.

and rosin from wood which comprises distilling -off volatile bodies f pm a resinous wood at a temperature insuflicient-to injure the rosin, and subsequently extracting the wood with a neutral volatile solvent to remove rosin. 1 i

2. The rocess of recovering turpentine and rosin rom wood which comprises distilling 'ofi turpentine from resinous Rood in a current of steam at a temperature below the bolling point of turpentine and subsequently extracting the wood with a neutral volatile solvent to remove rosin. I 3. The process of recovering turpentine and rosin from wood which comprises distllllng off turpentine from resinous wood in a current of steam at a temperature below the boiling point of turpentine, drying the woodto remove the steam and subsequently extractmg the wood with a neutral volatile solvent to remove rosin.

4. The process of recoveringlvaluable products from coniferous woods which com risesextracting such woods with a neutra lowboiling distillate from hardwood tar.

5. The process of recoverin turpentine and rosin which comprises dist ng ofi turentine-from a resinous wood in a current of ow pressure steam and subse uently extractin rosin from the wood wit a neutral entine from a resinous wood in a current of ow pressure steam, drying the wood to remove the steam'and subsequently extracting the wood with a neutral low-boiling distillate volatile solvent.

8. The process of recovering valuable prod ucts from reslnous wood which comprises placing such wood in a suitable container,

istilling ofi turpentine in the presence of aqueous vapor ata low pressure and tempera.- ture, removing such vapor from container and wood and extracting rosin from the wood remaining in the container witha neutral volatile solvent. I v

9. The rocess of recovering rosin from wood whic comprises placing comminuted resinous wood in a suitable container, distilling ofi turpentine and volatile bodies in a current of steam at a temperature below the boiling point of turpentine, removing steam and moisture from the'wood in said container, extracting the rosin from the treated wood with a neutral volatile solvent and recovering the rosin from the rosin solution so formed. a

10. The process of recovering turpentine and rosin from Wood, which comprises dis-' tilling ofi turpentine from resinous wood in a current of steam at a temperature below the boiling point of turpentine the passage of said steam being continued untl substantially no more volatile products are carried over thereby, and subsequentl extracting the wood with a neutral-volati e solvent to,

remove rosin.

In testimony whereof I afiix my signature in the presence of two subscribing witnesses.

GEORGE WALKER. Witnesses:

WILLIAM E. REILLY, FRANCES FORESTER.

It is hereby certified that in Letters Patent No. 922,369, granted May 18, 1909,

upon the application of George Walker, of New York, N. Y., for an improvement in Processes of Extracting Resin and Turpentine, an error appears in the printed specification requiring correction, as follows Inline 26, page 4, the word Rood should read wood; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 8th day of June, A. 11,1909.

[SEAL.] G. C. BILLINGS,

Acting Commissioner of Patents. 

